DEVELOPMENT OF THE WOLFFIAN BODIES, ETC. 



683 



FIG. 231. 



INTERNAL ORGANS OF GENERA- 

 TION, in a foetal pig 7% centi- 

 metres long. 1, 1. Kidneys. 2, 

 2. Wolffian bodies. s. Internal 

 organs of generation ; testicles 

 or ovaries. 4. Urinary bladder, 

 turned over in front. 5. Intes- 

 tine. 



deferentia at an early period are disconnected from the testicles ; origi- 

 nating, like the Fallopian tubes, by free extremities, with an open orifice. 

 Afterward they become adherent to the testicles, and establish a com- 

 munication with the tubuli seminiferi. In the human female, the Fal- 

 lopian tube remains disconnected from the 

 ovary, except at one point of its fimbriated 

 extremity ; but in many animals the greater 

 part of this extremity becomes adherent to 

 the ovary, which it envelops more or less 

 completely in a distinct sac. 



Male Organs of Generation; Descent of 

 the Testicles. In the male foetus there now 

 commences a change in position of the in- 

 ternal organs of generation, known as the 

 ''descent of the testicles." In consequence 

 of this change, the testicles, which are at 

 first in front of the kidneys, near the middle 

 of the abdomen, come to be situated in the 

 scrotum, outside the abdominal cavity, and 

 enclosed in a distinct sac, the tunica vagi- 

 nalis testis. This apparent movement re- 

 sults from a disproportionate growth of the abdominal organs above 

 the testicles, by which their relative position becomes altered. 



By the upward enlargement of the kidneys, both the Wolffian bodies 

 and the testicles are made to occupy 

 an inferior position (Fig. 232). At 

 the same time, a slender rounded 

 cord (not represented in the figure) 

 passes from the lower extremity of 

 each testicle outward and downward, 

 crossing the vas deferens a short dis- 

 tance above its union with that of 

 the opposite side. Below this point, 

 the cord spoken of continues to run 

 obliquely outward and downward: 

 and, passing through the inguinal 

 canal, is inserted into the subcuta- 

 neous tissue near the symphysis 

 pubis. The lower part of this cord 

 becomes the gubernaculum testis. 

 It contains muscular fibres, which 



are easily detected, in the human foetus, during the latter half of intra- 

 uterine life. At the period of birth, or soon after, they have usually 

 disappeared. 



That portion of the excretory tube of the testicle situated outside 

 the crossing of the gubernaculum, becomes afterward convoluted, and 

 converted into the epididymis. Inside this point the tube remains 



FIG. 232. 



INTERNAL ORGANS OF GENERATION in a foetal 

 pig nearly 10 centimetres long. 1, 1. Kid- 

 neys. 2, 2. Wolffian bodies. 3, 3. Testicles. 

 4. Urinary bladder. 5. Intestine. 



